Pay One or Pay All: Random Selection of One Choice for Payment

It has become increasingly common in economics experiments to elicit a series of choices from participants, and then pay for only one, selected at random, after all have been made. This allows the researcher to observe a large number of individual decisions, and to increase payoffs for each decision since only one of them will be used for payment. It has not been demonstrated, however, whether subjects behave as if each of these choices involves the stated payoffs, or if subjects scale-down payoffs to account for the random selection that is made. This paper reports an experiment that tests this directly. In an environment where payoff scale effects have been demonstrated to matter, three treatments are conducted: pay for one of 10 choices under low payoffs, pay for all 10 choices under low payoffs, and pay for 1 of 10 choices under 10x the low payoff level. Increasing payoff scale has a significant effect on choices compared with the low payoff treatments where all 10 decisions are paid, or where one decision is paid. However, there is no significant difference in choices between paying for one or all 10 decisions at the low payoff level. This supports the validity of using the random-choice payment method.

Risk Aversion and Incentive Effects

A menu of paired lottery choices is structured so that the crossover point to the high-risk lottery can be used to infer the degree of risk aversion. With "normal" laboratory payoffs of several dollars, most subjects are risk averse and few are risk loving. Scaling up all payoffs by factors of twenty, fifty, and ninety makes little difference when the high payoffs are hypothetical. In contrast, subjects become sharply more risk averse when the high payoffs are actually paid in cash. A hybrid "power/expo" utility function with increasing relative and decreasing absolute risk aversion nicely replicates the data patterns over this range of payoffs from several dollars to several hundred dollars

The Impact of Insurance Prices on Decision-Making Biases: An Experimental Analysis

This paper tests whether the use of endogenous risk categorization by insurers enables consumers to make better-informed decisions even if they do not choose to purchase insurance. We do so by adding a simple insurance market to an experimental test of optimal (Bayesian) updating. In some sessions, no insurance is offered. In others, actuarially fair insurance prices are posted, and a subset of subjects is allowed to purchase this insurance. We find significant differences in the decision rules used depending on whether or not one observes insurance prices. Although the majority of choices correspond to Bayesian updating, the incidence of optimal decisions is higher in sessions with an insurance option. Most subjects given the option to purchase actuarially fair insurance choose to do so, however fewer subjects purchase insurance when the probability of a loss is higher. Working Paper 06-1

Enhancing and Improving Designs for Auction Mechanisms that Can Be Used by the EPD for Irrigation Auctions

In March, 2001 the first Flint River Drought Protection Act Auction was conducted. This iterative sealed offer auction was held at eight sites in the Flint River Basin. Several hundred farmers participated, and a total of 33,006 acres were taken out of irrigation at an average cost of $136 per acre. This report describes some factors that led us to consider alternative auction institutions, the results of laboratory experiments that explore different auction rules, and the eventual outcome of the 2002 Irrigation Auction. Working Paper # 2002-01

Further Reflections on Prospect Theory

This paper reports a new experimental test of prospect theoryâ??s reflection effect. We conduct a sequence of experiments that allow us to directly compare choices under reflected gains and losses where real and hypothetical payoffs range from several dollars to over $100. Lotteries with positive payoffs are transformed into lotteries over losses by reflecting all payoffs around zero. When we use hypothetical payments, more than half of the subjects who are risk averse for gains turn out to be risk seeking for losses. This "reflection effect" is diminished considerably with cash payoffs, where the modal choice pattern is to exhibit risk aversion for both gains and losses. However, we do observe a significant difference in risk attitudes between losses (where most subjects are approximately risk neutral) and gains (where most subjects are risk averse). Reflection rates are further reduced when payoffs are scaled up by a factor of 15 (for both real and hypothetical payoffs).

Altruism Spillovers: Are Behaviors in Context-Free Experiments Predictive of Altruism Toward a Naturally Occurring Public Good?

This paper addresses the external validity of experiments investigating the characteristics of altruism in the voluntary provision of public goods. We conduct two related experiments that allow us to examine whether individuals who act more altruistically in the context-free environment are also more likely to act altruistically toward a naturally-occurring public good. We find that laboratory behavior can be predictive of contributions toward naturally-occurring goods, but not in a uniform way. In fact, parametric measures of altruism do a poor job of predicting which subjects are most likely to contribute to a naturally-occurring public good.

Altruism and Noisy Behavior in One-Shot Public Goods Experiments

An increase in the common marginal value of a public good has two effects: it increases the benefit of a contribution to others, and it reduces the net cost of making a contribution. These two effects can be decomposed by letting a contribution have an "internal" return for oneself that differs from the "external" return to someone else. We use this framework in a series of one-shot public goods games in which subjects make choices in ten treatments with no feedback. Contributions are generally increasing in the external return and group size, which suggests that altruism in this context is not simply of the "warm glow" variety, i.e. giving only for the sake of giving. Contributions are also increasing in the internal return, indicating that decisions are sensitive to the costs of helping others. We specify a logit equilibrium model in which individuals are motivated by own and others' earnings, and in which choice is stochastic. Maximum likelihood estimates of altruism and logit error parameters are significant and of reasonable magnitudes, and the resulting two-parameter model tracks the pattern of contributions across the ten treatments remarkably well.public goods, voluntary contributions, marginal per capita return, internal return, external return, bounded rationality, logit equilibrium, altruism, nonlinear altruism, warm glow altruism, one shot game

Using Laboratory Experiments For Policy Making: An Example From The Georgia Irrigation Reduction Auction

In April 2000, the Georgia legislature passed a law requiring that the state use an unspecified "auction-like process" to pay some farmers to suspend irrigation in declared drought years. In response, we conducted a series of laboratory and field experiments to test a variety of auction procedures. This paper reports the results of these experiments, and how they were used by the policy makers who determined the auction procedures. Experimental results are compared with farmers' bidding behavior in the state-run irrigation auction conducted in March 2001. Working Paper # 2002-00

Comparing Small-Group and Individual Behavior in Lottery-Choice Experiments

Lottery-choice experiments are conducted to compare risk preferences revealed by three-person groups versus isolated individuals. A lottery-choice experiment consists of a menu of paired lottery choices structured so that the crossover point from a low-risk to a high-risk lottery can be used to infer the degree of risk aversion. A between-subjects experiment of group versus individual lottery-choice decisions reveal that there is not a significant difference in the average crossover point, but lottery choices are affected by a significant interaction between subject composition (individual or group) and lottery winning percentage. Also, a three-phased individual-group-individual sequenced experiment reveals that the count of safe lotteries chosen by groups is, on average, significantly greater than the mean of the individual members. Finally, making a phase-two group decision has a significant impact on subsequent phase-three individual decisions relative to the initial phase-one (individual) decisions.lab experiments, risk preferences, group decisions

Comparing Small-Group and Individual Behavior in Lottery-Choice Experiments

Lottery-choice experiments are conducted to compare risk preferences revealed by three-person groups versus isolated individuals. A lottery-choice experiment consists of a menu of paired lottery choices structured so that the crossover point from a low-risk to a high-risk lottery can be used to infer the degree of risk aversion. A between-subjects experiment of group versus individual lottery-choice decisions reveal that there is not a significant difference in the average crossover point, but lottery choices are affected by a significant interaction between subject composition (individual or group) and lottery winning percentage. Also, a three-phased individual-group-individual sequenced experiment reveals that the count of safe lotteries chosen by groups is, on average, significantly greater than the mean of the individual members. Finally, making a phase-two group decision has a significant impact on subsequent phase-three individual decisions relative to the initial phase-one (individual) decisions.lab experiments, risk preferences, group decisions